Basic Docker Notes

To run a container from an image:

1docker container run -it --rm ubuntu /bin/bash

-t: terminal inside
-i: (STDIN) grabbing
–rm: remove container automatically when process exits
–name: name the container or daemon
-d: daemonize the container running

To list all containers:

1docker container ps -a

To start or stop container:

1docker container stop container_name

To remove container(s):

1docker container rm -f $(docker container ps -aq)

-q: print only container IDs

To run a container as a daemon:

1docker container run -d --name "test-nginx" -p 8080:80 -v $(pwd):/usr/share/nginx/html:ro nginx:latest

-p: port mapping, local_port:container_port
-v: volume mounting, host_dir:container_dir
$(pwd): current working dir

To check the information of image/container/volume/network:

1docker container inspect container_name

To write a basic Dockerfile:

1FROM        #Set base image
2RUN         #Execute command in container
3ENV         #Set environment variable
4WORKDIR     #Set working directory
5VOLUME      #Create a mount point for a volume
6CMD         #Set executable for container

To build an image from Dockerfile:

1docker build -t image_name .

.: means context is the current working directory.
-t: sets a name for the image

To install docker and docker composer on Debian:

1apt update -y
2apt install docker.io docker-compose -y

To access to the docker daemon as a non-root user

1groupadd docker
2usermod -a -G docker $USER

Rule of thumb

  • 1 app = 1 container
  • Process should be running in the foreground
  • Keep data in volumes, not in containers
  • Do not use SSH, use docker exec instead
  • Avoid manual configurations inside container

Happy dockerizing, Gents! 🙂

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